This invention relates primarily to the art of sewage treatment and, more particularly, to treatment of sewage in a recirculating-type of toilet.
Toilets of the recirculating-type are commonly used on recreational vehicles and boats, and in other locations where a plentiful fresh water supply and sewage disposal facilities are lacking. These toilets include a storage chamber which is charged with a relatively small quantity of clear water and liquid from the storage chamber is recirculated through the bowl back into the storage chamber for flushing purposes. Human wastes deposited in the storage chamber mix with the initial water charge and form part of the flushing liquid thereafter.
Toilets of the type described commonly have a chemical added to the liquid in the storage chamber for destroying coliform and other bacteria in the liquid, and for reducing odor-producing gases. In other arrangements, reagents are added to the storage chamber periodically or are generated electrolytically within the storage chamber from chemicals dissolved in the liquid in the storage chamber. Previous recirculating toilets of this type have included macerating means for macerating solids in an attempt to return same to a liquid form for recirculation through the bowl for flushing purposes.
Even though sewage solids are generally decomposable to a liquid, decomposition of the solids back to liquid form takes a relatively long period of time. Macerating the solids simply creates a large amount of suspended solids in the liquid contained in the storage chamber. These solids are fed back to the bowl for flushing purposes, and coliform or the like may not be completely destroyed by chemicals in the storage chamber because it requires time for the chemicals to attack the coliform contained within the solid particles. Solids containing live bacteria build up in the flush water to cause odors and create a health hazard.
The present invention successfully overcomes the above-noted problems as well as others and provides a recirculating toilet which is simple, economical, and readily adaptable to use in many environments.
Typical of such prior art patents is U.S. Pat. No. 3,595,786. This patent describes treating fluids in a hold tank with disinfecting chemicals such as calcium hypochlorite before the liquid flush water is returned to the toilet bowl. In this patent, however, the amount of sanitizing agent dispensed to the fluid or flush water can vary widely, since the time period between flushing can vary widely, and secondly the flush liquid need not necessarily come in close proximity to said sanitizing tablets while passing through the hold or storage tank.